6 nonlocal jumps 439 codeecfsetjmpc 1 2 3 4 5 6 7 8 9

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Unformatted text preview: n sends signal number sig to process pid. If pid is less than zero, than kill sends signal sig to every process in process group abs(pid). Figure 8.25 shows an example of a parent that uses the kill function to send a SIGKILL signal to its child. Sending Signals With the alarm Function A process can send SIGALRM signals to itself by calling the alarm function. #include <unistd.h> unsigned int alarm(unsigned int secs); returns: remaining secs of previous alarm, or 0 if no previous alarm The alarm function arranges for the kernel to send a SIGALRM signal to the calling process in secs seconds. If secs is zero, then no new alarm is scheduled. In any event, the call to alarm cancels any pending alarms, and returns the number of seconds remaining until any pending alarm was due to be delivered (had 426 CHAPTER 8. EXCEPTIONAL CONTROL FLOW code/ecf/kill.c 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 #include "csapp.h" int main() { pid_t pid; /* child sleeps until SIGKILL signal received, then dies */ if ((pid = Fork()) == 0) { Pause(); /* wait for a signal to arrive */ pr...
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This note was uploaded on 09/02/2010 for the course ELECTRICAL 360 taught by Professor Schultz during the Spring '10 term at BYU.

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